If Manchester Airport officials discover a man who is unwilling to proceed through customs and officially enter the United Kingdom later this month, the chances are that he will look somewhat familiar. Robinho is due back at Manchester City after his six-month loan at Santos.

The reluctant returnee is a footballer who was meant to epitomise the new, moneyed City but is becoming an indictment of overspending and his journey from marquee signing to unwanted embarrassment has taken just two years. At Santos, he was out of sight and, at times, out of mind. That is not possible in Manchester. There he becomes a one-man example of the danger of buying the wrong characters. There are hints that the Premier League's most expensive footballer could become the most high-profile victim of the 25-man squad rule. Even if that is not the case, David Silva and - should he sign - Mario Balotelli look like direct replacements while Craig Bellamy displaced the Brazilian from the team last year.

It is a question of suitability, not one of ability. Few of the Premier League players to feature at the World Cup performed better than Robinho, yet his lackadaisical approach in City's colours, tendency towards anonymity away from Eastlands and continued unhappiness in England suggest he is better off elsewhere.

Where his tale differs from those of other misguided signings, however, is in the money and its consequences. Robinho was priced at £32.4 million when City signed him and is paid £160,000 a week; it makes his plight different to those of lesser players. Santos cannot afford him - it has become apparent during his loan spell in his homeland - and nor, by extension, can any other South American club. Indeed, very few can.

So Robinho may find himself trapped, against his will, perhaps, but definitely because of his cost. Unless a compromise is reached either by City, reducing their asking price to take a huge loss on him, or the player himself, by accepting substantially lower wages, he is stuck at Eastlands. City can afford it, but that does not make them natural benefactors towards other clubs - not at a time when they are attempting to get value for money when signing. Robinho may not like the idea of a pay cut, but it may be his only method of escape.

Rather than symbolising City, his new role may be as the figurehead of another group: the men who are stuck at the club. His friend and fellow Brazilian Jo cost £18 million, proof that a combination of Thaksin Shinawatra, agents and buying on the never-never made for disastrous business.

Since then, City have been able to loan him out, but not offload him. Jo was offered in part-exchange when Joleon Lescott was signed from Everton a year ago, though the Brazilian was between two short-term stints at Goodison Park and David Moyes did not want him included in the deal. Quite simply, he had no need to. Jo could be borrowed again without any cost and with City still paying some of his wages, while when he became surplus to requirements, he could be let go without any added complications.

If City are unlikely to buy quite as badly again, it is an issue of increasing significance. With each signing, another player loses his place in the pecking order. And if he is a footballer bought, or given a new contract, since Sheikh Mansour's takeover, the chances are he is disproportionately well rewarded.

Take Wayne Bridge (an offer that may soon be made to rival clubs). When he joined from Chelsea in January 2009, the Englishman was reportedly the best-paid full-back in the world. Not that, when most deserving candidates included Maicon, Dani Alves and Philipp Lahm, he could ever be called the planet's best full-back. And now, after the arrival of Aleksandar Kolarov, he is probably not City's first-choice left-back; indeed, factor in Jerome Boateng's World Cup performances there for Germany, he may only be the third in line.

Bridge's Chelsea career suggests he can tolerate a well-remunerated life on the bench. If he cannot, the likelihood is that City will have to subsidise his employment elsewhere. Left-backs rarely tend to be the highest earners elsewhere and Bridge is no Patrice Evra or Ashley Cole.

The more immediate future could contain moves for Stephen Ireland, Craig Bellamy or Roque Santa Cruz. For each, the size of his pay packet acts as a deterrent (Ireland signed a new deal in 2009, the year Bellamy and Santa Cruz arrived). For each, a move may only be facilitated if City contribute to their earnings elsewhere.

Rewind a few years, however, and City were the beneficiaries of another's desperation to shed players. Robbie Fowler's time at Eastlands was undistinguished, but it was financed in part by Leeds, who had to pay players to represent other clubs after the excesses of the Peter Ridsdale era.

City's spending may not have the apocalyptic consequences of Leeds', where two relegations and administration followed. They can afford to pay over the odds but, as Robinho proves, it is still a risky policy if they don't choose their targets more carefully.